Interactive sealing arrangement pressurized fluid storage system and method

ABSTRACT

An interactive sealing arrangement includes a sealing member operatively disposed across a gap between a first wall and a second wall that is moveable relative to the first wall and at least partially defines a storage chamber. A passage extends through the second wall and is in fluid communication with the sealing member such that a portion of an associated fluid at an elevated pressure within the storage chamber can interact with the sealing member and thereby urge at least a portion of the sealing member into abutting engagement with the first wall. A pressurized fluid storage system for containing a quantity of an associated fluid at an elevated pressure level that includes such an interactive sealing arrangement and a method of sealing are also included.

This application claims the benefit of priority from U.S. ProvisionalPatent Application No. 61/183,621, filed on Jun. 3, 2009; U.S.Provisional Patent Application No. 61/181,365, filed on May 28, 2009;and U.S. Provisional Patent Application No. 61/106,963, filed on Oct.20, 2008, each of which is hereby incorporated herein by reference inits entirety.

BACKGROUND

The subject matter of the present disclosure broadly relates to the artof pressure vessels and, more particularly, to an interactive sealingarrangement for use in storing pressurized fluids as well as apressurized fluid storage system and method that utilize the same.

Pressure vessels and sealing arrangements are generally well known andcommonly used. With the continued interest in developing alternativeenergy sources, new applications and/or uses for pressure vessels may bedeveloped for which known pressure vessels and/or sealing arrangementsmay be inadequate. In some cases, the capability of known pressurevessels to achieve desired levels of compression, such as for thestorage of liquids and/or gases, for example, may be insufficient. Inother cases, known sealing arrangements may be incapable of maintainingpressurized fluids at these desired levels of compression for sufficientperiods of time.

Accordingly, it is believed desirable to develop sealing arrangements aswell as pressurized fluid storage systems and methods that advance theart of pressure vessels and high pressure sealing arrangements.

It will be appreciated that the subject concepts may find particularapplication and/or use in connection with the compression and storage ofliquids and/or gases associated with usage as or in connection withenergy sources. As such, substances such as hydrogen, natural gas andliquefied natural gas, for example, may be specifically referred toherein. Additionally, applications associated with the manufacture ofenergy sources as well as the storage of fuel on moveable vehicles (e.g.watercraft, aircraft and/or land vehicle) are also contemplated.However, it is to be distinctly understood that the subject concepts arebroadly applicable in connection with a wide variety of applicationsand/or uses, and that any particular reference herein to specificapplications and/or uses are merely exemplary and not intended to belimiting.

BRIEF SUMMARY

One example of a pressurized fluid storage system in accordance with thesubject matter of the present disclosure for containing a quantity of anassociated fluid at an elevated pressure level can include a pressurevessel including a vessel wall that at least partially defines a storagechamber for storing a quantity of the associated fluid. The vessel wallcan include an opening providing access to said storage chamber. Amoveable wall structure can be displaceably supported within thepressure vessel and can extend across the opening to at least partiallyretain a quantity of the associated fluid in the storage chamber. Themoveable wall structure can include an outer peripheral wall disposedadjacent the vessel wall such that a gap is formed between the outerperipheral wall and the vessel wall. An end wall can be disposed towardthe storage chamber. A groove can extend into the moveable wallstructure from along the outer peripheral wall such that the groove isin fluid communication with the storage chamber through the gap. Atleast one passage can extend through at least a portion of the moveablewall structure and in fluid communication between the groove and thestorage chamber. An interactive sealing arrangement can be operativelydisposed between the pressure vessel and the moveable wall structure andcan be capable of forming a substantially fluid-tight seal therebetween.The interactive sealing arrangement can include a first sealing memberthat is positioned between the moveable wall structure and the vesselwall and is disposed at least partially within the groove of themoveable wall structure. The first sealing member can include a firstperipheral portion disposed toward the vessel wall and a secondperipheral portion disposed along the groove in fluid communication withthe at least one passage such that a portion of the associated fluid atan elevated pressure within the storage chamber can interact with thesecond peripheral portion of the first sealing member and thereby urgethe first peripheral portion of the first sealing member into abuttingengagement with the vessel wall of the pressure vessel.

One example of an interactive sealing arrangement in accordance with thesubject matter of the present disclosure, which is suitable for use onan associated pressurized storage container having an associatedcontainer wall that at least partially defines an associated storagechamber for containing a quantity of an associated pressurized fluid,can include a first wall and a sealing member. The first wall ismoveable with respect to the associated container wall and at leastpartially defines the associated storage chamber together therewith. Thefirst wall includes an outer peripheral surface that is disposedadjacent the associated container wall. An end surface is disposedtoward the associated storage chamber. A groove extends into the firstwall from along the outer peripheral surface. At least one passageextends through the first wall in fluid communication with the groove.The sealing member is at least partially disposed within the groovebetween the first wall and the associated container wall. At least aportion of the sealing member is in fluid communication with theassociated pressurized fluid through the passage such that theassociated pressurized fluid can interact with the sealing member andthereby urge at least a portion of the sealing member into abuttingengagement with the associated container wall.

One example of a method of storing pressurized fluid in accordance withthe subject matter of the present disclosure can include providing afirst wall that includes a first wall surface at least partiallydefining a storage chamber having a volume. The method can also includeproviding a second wall that is displaceable relative to the first wallto vary the volume of the storage chamber. The second wall can includean outer side surface, a groove formed into the second wall along theouter side surface and a first passage extending through at least aportion of the second wall and in fluid communication with the groove.The outer side surface can be spaced inwardly from the first wallsurface such that a gap is at least partially formed therebetween. Themethod can further include positioning a sealing member within thegroove and between the first and second walls. The method can alsoinclude pressurizing a quantity of fluid within the storage chamber. Themethod can further include exposing a first portion of the sealingmember to the quantity of pressurized fluid through the gap. The methodcan also include exposing a second portion of the sealing member to thequantity of pressurized fluid through the first passage such that thequantity of pressurized fluid interacts with the sealing member andthereby urges the first portion of the sealing member into abuttingengagement with the first wall surface of the first wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of one example of a pressurizedfluid storage system that includes a moveable wall and an interactivesealing arrangement in accordance with the subject matter of the presentdisclosure.

FIG. 2 is a cross-sectional side view of a portion of the pressurizedgas storage system in FIG. 1 illustrating the moveable wall and theinteractive sealing arrangement thereof in additional detail.

FIG. 3 is an exploded isometric view of the moveable wall and theinteractive sealing arrangement in FIGS. 1 and 2.

FIGS. 4 and 5 are cross-sectional side views of another example of apressurized fluid storage system that includes an alternate embodimentof a moveable wall and an interactive sealing arrangement in accordancewith the subject matter of the present disclosure respectively shown inmoveable and sealed conditions.

FIG. 6 is an enlarged cross-sectional side view of the portion of theinteractive sealing arrangement identified in Detail 6 of FIG. 5.

FIGS. 7-9 are cross-sectional side views of yet another example of apressurized fluid storage system that includes yet another alternateembodiment of a moveable wall and an interactive sealing arrangement inaccordance with the subject matter of the present disclosurerespectively shown being transferred from a moveable condition to asealed condition.

FIG. 10 is an enlarged cross-sectional side view of the portion of theinteractive sealing arrangement identified in Detail 10 of FIG. 7.

FIG. 11 is a cross-sectional side view of still another example of apressurized fluid storage system that includes still another alternateembodiment of a moveable wall and an interactive sealing arrangement inaccordance with the subject matter of the present disclosure shown in amovable condition.

FIG. 12 is an enlarged cross-sectional side view of another example of asealing element suitable for use in an interactive sealing arrangementin accordance with the subject matter of the present disclosure.

FIG. 13 is an enlarged cross-sectional side view of yet another exampleof a sealing element suitable for use in an interactive sealingarrangement in accordance with the subject matter of the presentdisclosure.

FIG. 14 is an enlarged cross-sectional side view of still anotherexample of a sealing element suitable for use in an interactive sealingarrangement in accordance with the subject matter of the presentdisclosure.

FIG. 15 is a greatly enlarged portion of the sealing element in FIG. 14taken along line 15-15 thereof.

FIG. 16 is an enlarged cross-sectional side view of a further example ofa sealing element suitable for use in an interactive sealing arrangementin accordance with the subject matter of the present disclosure.

DETAILED DESCRIPTION

Turning to the drawings, which illustrate examples of the subject matterof the present disclosure and which are not intended to be in any waylimiting, FIG. 1 illustrates a pressurized fluid storage system 100 thatincludes a pressure vessel, including at least one vessel wall, such asa container or storage structure 102, for example, a moveable wall, suchas a piston 104, for example, that is at least partially received withinthe storage structure, and a sealing arrangement 106 that is operativelydisposed therebetween. In a preferred embodiment, sealing arrangement106 can take the form of an interactive sealing arrangement thatutilizes the pressurized fluid (e.g., gas and/or liquid) stored withinstorage structure 102 to urge a sealing member or element of the sealingarrangement into abutting engagement with the storage structure and/orthe moveable wall. It is anticipated that such an arrangement will actto increase the effectiveness of the seal (i.e., the barrier) formed bythe sealing arrangement, particularly at elevated pressure levels. Asone example, a sealing member or element of the sealing arrangement canbe placed in fluid communication with the pressurized fluid (e.g., gasand/or liquid) stored within the storage structure, such as by way ofone or more fluid passages extending through the moveable wall, forexample. It will be appreciated, however, that the arrangements shownand described herein are merely examples of suitable arrangements andthat any other designs, configurations and/or constructions inaccordance with the subject matter of the present disclosure couldalternately be used.

Storage structure 102 includes at least one wall that at least partiallydefines a storage chamber suitable for storing or otherwise containing aquantity of fluid at an elevated pressure level. In the example shown inFIGS. 1 and 2, storage structure 102 includes a first or side wall 108and a second or end wall 110 that together define a storage chamber 112.If two or more walls are used, it will be appreciated that the same canbe secured to one another in any manner capable of forming asubstantially fluid-tight connection of suitable strength, such asthrough the use of a flowed-material joint JNT, for example.

The moveable wall can be of any suitable type, kind, configurationand/or construction, and can formed from or otherwise include anysuitable number of one or more wall portions, segments and/or othercomponents. For example, the moveable wall could be formed from two ormore axially aligned (e.g., stacked) wall sections (not shown) that aresecured to one another using one or more fasteners (not shown) tothereby form the moveable wall. Further to the above example, a first orinner wall section (not shown) having a first cross-sectional dimensioncould be secured between two second or outer wall sections (not shown)that have a second, greater cross-sectional dimension. The inner andouter wall sections could be secured together using a fastener (notshown) and, in this manner, an annular groove for receiving a sealingelement of the sealing arrangement could be provided. It will beappreciated, however, that any other suitable arrangement and/orconstruction could alternately be used.

In the arrangement illustrated in FIGS. 1 and 2, piston 104 can includean outer peripheral wall 114 that extends in a generally longitudinaldirection between a first or inner end wall 116 and a second or outerend wall 118 of the piston. The moveable wall can be actuated orotherwise displaced in any suitable manner and through the use of anysuitable device and/or system. As one example, a piston rod 120 is shownas operatively engaging piston 104 and projecting longitudinally fromouter end wall 118 thereof in a direction opposite storage chamber 112.Piston rod 120 can extend from a suitable actuator or actuating device,such as a hydraulic cylinder (not shown), for example, that is capableof displacing the piston relative to the vessel wall (e.g., towardand/or away from end wall 110 of storage structure 102).

It is contemplated that a sealing arrangement in accordance with thesubject matter of the present disclosure will permit the storage offluids (e.g., gases and/or liquids) at pressures that may exceed thecapacity of presently available pumps or fluid pumping systems that maybe used to transfer fluids into the storage chamber. In order to achievethe desired high pressure levels for storing fluids, pressurized gasstorage system 100 is shown as optionally including a second storagestructure section 122 that is operatively interconnected with a firststorage structure section, such as storage structure 102, for example.Second storage structure 122 includes a first or side wall 124 thatextends longitudinally between opposing ends 126 and 128 to at leastpartially define an extended portion 112A of storage chamber 112. Sidewall 124 can be operatively interconnected with side wall 108 of storagestructure 102 such that a substantially fluid-tight seal is formedtherebetween, as is generally indicated by item number 130.

Additionally, side walls 108 and 124 are preferably cooperable with oneanother such that a substantially uniform and continuous inner surface132 of the storage structure is provided, such as may extendcircumferentially about a longitudinally-extending axis AX (FIG. 2), forexample. Such an arrangement would permit piston 104 to be receivedwithin storage chambers 112 and 112A, and displaced along inner surface132 to pressurize the quantity of fluid within the storage structure,such as is discussed hereinafter, for example. In one preferredarrangement, piston 104 can be approximately circular in cross-sectionand can be received within the storage chamber in closely fittedrelation to inner surface 132 of the storage structure. In such case,inner surface 132 can, for example, be substantially cylindrical inshape.

In use, piston 104 can be stationed at a first or extended position,which is indicated by reference character A in FIG. 1, toward end 126 ofsecond storage structure section 122. A pump 134 can be in fluidcommunication with storage chamber 112 (including storage chamberportion 112A), and can operate to supply a quantity of fluid into thestorage chamber at a suitable pressure. One example of a suitablepressure may be the highest pressure level that is practical to achieveusing pump 134, such as a pressure level within a range of approximately300 psi to approximately 2000 psi, for example. Piston 104 can then beadvanced through the use of a suitable actuator, such as may beoperatively connected to piston rod 120, for example, along secondstorage structure section 122 to a second or compressed position withinstorage structure 102, as is indicated by reference character B in FIG.1.

It will be recognized that the displacement of piston 104 from positionA to position B will act to compress a gas or gas/liquid mixture withinstorage chamber 112, such as for storage or transportation, for example.It is expected that a compression ratio of approximately 10:1 or greatermay be feasible using such a construction and that a sealing arrangementin accordance with the subject matter of the present disclosure will becapable of maintaining compressed gas (or a gas/liquid mixture) at theresulting high pressure level. For many applications, it is expectedthat it will be desirable to eliminate the force used to compress thegas once the desired degree of compression has been achieved. This canbe accomplished by locking piston 104 in the second or compressedposition (e.g., position B), such as by using deadlock devices 136, forexample.

In some cases, it may be possible for the second storage structuresection (e.g., section 122) to be used only for the period during whichcompression takes place. Accordingly, second storage structure section122 can be removably attached to storage structure 102 such that thesame can be removed after the compression action is completed. In oneembodiment, storage structure 102, which could be used to contain thecompressed gas, could be of a smaller size (e.g., shorter length). Insuch case, once the compression has been completed, second storagestructure section 122 could be removed, which may allow for easieraccess and handling of the smaller portion (i.e., storage structure102).

As illustrated in FIGS. 1 and 2, outer peripheral wall 114 is disposedin radially-inwardly spaced relation with respect to inner surface 132of the storage structure. As such a clearance or gap 138 is providedbetween the piston and storage structure that permits the piston to bedisplaced relative thereto. It will be appreciated, however, that such aclearance or gap is not to scale and is shown as having an exaggerateddimension for purposes of ease of illustration. In a preferredembodiment, the actual separation will preferably be the least allowablewith reasonable and practical machining and manufacturing processes,such as within a range of from about 0.0005 inches to about 0.050inches, for example.

It will be appreciated that a moveable wall and an interactive sealingarrangement in accordance with the subject matter of the presentdisclosure can include any arrangement and/or configuration of featuresand/or components that are suitable for bridging the gap (e.g., gap 138)between the storage structure and the moveable wall and thereby at leastpartially forming a substantially fluid-tight seal between the storagestructure and the moveable wall. It will be further appreciated that anysuch features and/or components can be provided on or along any walls orsurfaces of any one or more components of pressurized fluid storagesystem 100 and in any suitable manner.

As one example, sealing arrangement 106 is shown as being operativelydisposed between piston 104 and storage structure 102 such that asubstantially fluid-tight seal can be formed therebetween. Such asealing arrangement can included one or more sealing members or elementsof any suitable size, shape, configuration, construction and/orarrangement. For example, the one or more sealing members or elementscould have a circular, oval, rectangular or other cross-sectional shape(e.g., quad-ring). Additionally, the one or more sealing members orelements can be formed from any suitable material or combination ofmaterials. In some cases, a sealing member may be formed from a singlematerial, such as flexible polymeric material (e.g., synthetic rubberand urethane), a rigid polymeric material (e.g., polyethylene,polypropylene and PTFE), a metal or any combination thereof. In othercases, a sealing member could be formed from one or more layers ofmaterials, such as a closed-cell foam, for example. In one sucharrangement, layers of different closed-cell foams could be formed in anested or annularly stacked arrangement, for example.

As a more specific example, sealing arrangement 106 is shown in FIGS.1-3 as including a sealing member or element 140 that extendscircumferentially about piston 104 adjacent inner surface 132 of sidewall 108. The sealing element is shown as being of a circular oroval-shaped cross section, such as a conventional o-ring, for example.It will be appreciated, however, that any other cross-sectional shape orconfiguration could alternately be used. Additionally, sealing element140 could be formed from a suitable elastomeric material, such as asynthetic rubber or urethane, for example.

The one or more sealing elements of sealing arrangement 106 can beoperatively interengaged with the moveable wall (e.g., piston 104) ofthe pressurized fluid storage system in any suitable manner. One exampleof a suitable construction is shown in FIGS. 1-3 in which piston 104includes a groove 142 or other suitable feature that extends about theperiphery of the piston (e.g., circumferentially about exterior surfaceof outer peripheral wall 114). It will be appreciated that the groove orother suitable feature can be of any suitable shape, form and/orconfiguration. In the exemplary arrangement shown in FIGS. 1-3, forexample, groove 142 is shown as being of a rectangular-shaped crosssection that includes a bottom wall 144 and opposing side walls 146 thatare axially-spaced from one another to at least partially define thegroove.

In the exemplary arrangements shown and described herein, the one ormore sealing elements (e.g., sealing member 140) are each at leastpartially received within a groove (e.g., groove 142) or other suitablefeature on or along the moveable wall (e.g., piston 104). In thismanner, the one or more sealing elements can be retained in position onpiston 104 as the piston is displaced in an axial direction, as isrepresented by arrow AR1 in FIG. 1.

During movement toward and away from a compressed position (e.g.,position B), it is normally desirable for a sealing arrangement, such assealing arrangement 106, for example, to generate a reduced level ofresistance to movement, such as may be due to friction generated bycontact with the storage structure, for example. In some cases, it maybe desirable for the sealing arrangement to generate little or noresistance to movement, as frictional movement is commonly associatedwith wear between the moving parts. In the compressed position, however,it is desirable for the one or more sealing elements (e.g., sealingmember 140) that form sealing arrangement 106 to bridge the gap ordistance between the moveable wall and the storage structure.Additionally, it is anticipated that some amount of fluid loss may occurduring transfer of the moveable wall into a compressed position. It isexpected, however, that such fluid loss should be minimal and withinacceptable limits. Optionally, a suitable exhaust and/or fluid recapturesystem (not shown) could be included.

One feature of a sealing arrangement in accordance with the subjectmatter of the present disclosure is the capability to increase sealingengagement as the moveable wall approaches the compressed position.While the distance the one or more sealing elements travel to bridge thegap between the moveable wall and the storage structure is expected tobe small, the compressive forces that are expected to be generated bythe one or more sealing elements, such as may be due to the same beingin fluid communication with the elevated pressure level of the containedfluid, is expected to allow containment at pressures beyond thosepresently attainable.

The actuation of the one or more sealing members from a first ormoveable condition to a second or compressed condition can be achievedin any suitable manner. As one example, one or more fluid passages canbe provided that extend through the moveable wall to permit fluidcommunication between the one or more sealing elements and thepressurized fluid contained in the storage chamber of the storagestructure. The elevated pressure level of the fluid contained in thestorage chamber acts to bias or otherwise urge at least a portion of theone or more sealing members into abutting engagement with a wall of thestorage chamber to form a substantially fluid-tight seal between themoveable wall and the storage structure.

It will be appreciated that the one or more fluid passages can take anysuitable size, shape, form, configuration and/or arrangement. In theexemplary embodiment shown in FIGS. 1-3, piston 104 includes twopassages 148 that extend through at least a portion of piston 104. Inthe exemplary arrangement shown, each passage includes a first opening150 that is provided on piston 104 in an area that is exposed to thepressurized fluid contained within the storage structure, such as alongend wall 116 of piston 104, for example. Each passage also shown asincluding a second opening 152 that is disposed adjacent one of thesealing elements (e.g., sealing element 140). In this manner,pressurized fluid from the storage chamber can be communicated to one ormore of the one or more sealing elements for biasing or actuationthereof.

In the exemplary arrangement shown in FIGS. 1-3, second openings 152 arepositioned such that the pressurized fluid is communicated in or alonggroove 142, such as by providing second openings 152 along bottom wall144, for example. It will be appreciated, however, that any othersuitable arrangement could alternately be used. Additionally, it will beappreciated that passages 148, together with the openings thereof, canbe of any suitable size, shape, quantity (e.g., a number within a rangeof from 1 to 50), configuration and/or arrangement. As one example, aminimal number of passages (e.g., from 1 to 10) are provided that extendthrough the piston from an area along end wall 116 that is disposedradially-inwardly from outer peripheral wall 114. One benefit of such anarrangement is that issues related to the structural integrity of thepiston can be minimized or even eliminated.

Another example of a pressurized fluid storage system 200 is shown inFIGS. 4-6 that includes an alternate embodiment of a moveable wall andan interactive sealing arrangement in accordance with the subject matterof the present disclosure. Storage system 200 includes a storagestructure 202, such as has been described above with regard to storagestructure 102, for example, as well as a moveable wall and aninteractive sealing arrangement. In the exemplary embodiment shown inFIGS. 4-6, the moveable wall includes a first piston 204 and theinteractive sealing arrangement is identified by item number 206.

Storage structure 202 is shown as including a first or side wall 208that at least partially defines a longitudinally-extending storagechamber 210 having a longitudinal axis AX. It will be appreciated thatside wall 208 and storage chamber 210 can be of any suitable type, kind,construction and/or configuration, such as has been described above indetail with regard to storage structure 102, for example. As such, afurther description of storage structure 202 is not provided here.

First piston 204 and sealing arrangement 206 differ from piston 104 andsealing arrangement 106 in several respects. For example, first piston204 is configured to permit selective actuation of sealing arrangement206, whereas the actuation of sealing arrangement 106 is relatesdirectly to the pressure level of the fluid confined in the storagechamber. As another example, sealing arrangement 206 is shown asincluding a plurality of sealing elements that at least partially defineat least one intermediate chamber between the storage chamber and theatmosphere external to the storage system. As a further example, sealingarrangement 206 is shown as including an optional migration-reducingsubstance disposed in the intermediate chamber, which substance may beused to reduce or otherwise minimize the migration of the pressurizedfluid stored within the storage chamber beyond the sealing arrangement.

In the exemplary embodiment in FIGS. 4-6, first piston 204 is shown asincluding a first outer peripheral or side wall 212 that extendsapproximately longitudinally between a first inner end wall 214 and afirst outer end wall 216. In a preferred arrangement, first outerperipheral wall 212 is cooperatively dimensioned with respect to sidewall 208 such that a clearance or gap 218 is provided between the firstpiston and the side wall of the storage structure, which gap permits thefirst piston to be displaced relative to the storage structure. It willbe appreciated that such a clearance or gap is not to scale and is shownas having an exaggerated dimension for purposes of clarity and ease ofillustration. In a preferred embodiment, the actual separation willpreferably be the least allowable with reasonable and practicalmachining and manufacturing processes, such as within a range of fromabout 0.0005 inches to about 0.050 inches, for example.

As discussed above, for example, first piston 204 can be actuated orotherwise displaced in any suitable manner and through the use of anysuitable device and/or system. As one example, a first piston rod 220projecting longitudinally from first outer end wall 216. Such a pistonrod can, for example, extend from a suitable actuating device, such as ahydraulic cylinder (not shown), for example, that is capable ofdisplacing the first piston with respect to the storage structure.

A sealing arrangement in accordance with the subject matter of thepresent disclosure, such as sealing arrangement 206, for example, caninclude any number of one or more sealing elements. In shown in theexemplary embodiment in FIGS. 4-6, sealing arrangement is shown asincluding a first sealing element or membrane 222 and a second sealingelement or membrane 224 that is disposed in longitudinally-spacedrelation to the first sealing element such that an intermediate chamber226 is at least partially defined therebetween. In the exemplaryembodiment shown, intermediate chamber 226 is further defined by sidewall 208 and first outer peripheral wall 212, and, in a preferredembodiment, extends circumferentially about first piston 204. Asdiscussed above, it will be appreciated that sealing elements 222 and224 can be of any suitable size, shape, type, kind, configuration,construction and/or arrangement, and can be formed from any suitablematerial or combination of materials.

As discussed above, a moveable wall and sealing arrangement inaccordance with the subject matter of the present disclosure can beadapted to permit selective actuation of the sealing arrangement betweena first or moveable condition and a second or sealed condition. In thefirst or moveable condition, the sealing arrangement provides minimizedor at least reduced interaction with at least one of the movable walland the storage structure so that the moveable wall can be more easilydisplaced. Such a condition may also minimize or at least reduce wear onthe sealing arrangement during displacement of the moveable wall. In thesecond or sealed condition, the sealing arrangement provides maximizedor at least significantly increased interaction with at least one of themoveable wall and the storage structure. Actuation of the sealingarrangement into the second or sealed condition can, for example, beperformed once the moveable wall has reached a predetermined position oronce the desired compression of the fluid contained in the storagestructure has been achieved.

It will be appreciated that the selective actuation of the sealingarrangement between a first or moveable condition and a second or sealedcondition, as discussed above, can be provided in any suitable mannerand using any suitable combination of components and/or features. In theexemplary arrangement shown in FIGS. 4-6, for example, first piston 204includes a cavity side wall 228 and a cavity end wall 230 that at leastpartially define an actuation cavity 232 that extends into first piston204 from along first inner end wall 214. A second piston 234 includes asecond inner end wall 236, a second outer end wall 238 and a secondouter peripheral or side wall 240 that extends longitudinallytherebetween. Second piston 234 is at least partially received withinactuation cavity 232 such that second outer peripheral wall 240 isdisposed in facing relation to cavity side wall 228. In a preferredarrangement, the second outer peripheral wall is spacedradially-inwardly from the cavity side wall such that a clearance or gap242 is at least partially defined therebetween.

As discussed above, second piston 234 is adapted for selective actuationbetween a first position, which is shown in FIG. 4, and a secondposition, which is shown in FIG. 5. It will be appreciated that thesecond piston can be displaced between the first and second positions inany suitable manner. In the exemplary arrangement shown in FIGS. 4 and5, first piston rod 220 includes an actuation passage 244 that extendslongitudinally therethrough and second piston 234 includes a secondpiston rod 246 that extends longitudinally from along second outer endwall 238. Second piston rod 246 is shown as extending through actuationpassage 244 such that second piston 234 can be selectively displacedrelative to first piston 204, such as, for example, through the use of asuitable actuation device (not shown) that is operatively connected tosecond piston rod 246.

In the first position of second piston 234, which is shown in FIG. 4, asubstantially fluid-tight seal is formed across gap 242 thatsubstantially fluidically-isolates actuation cavity 232 from storagechamber 210. In the second position of the second piston, which is shownin FIG. 5, a substantially fluid-tight seal is formed across gap 242that substantially fluidically-isolates actuator passage 244 fromstorage chamber 210. It will be appreciated that such substantiallyfluid-tight seals can be formed in any suitable manner. In the exemplaryarrangement shown in FIGS. 4 and 5, a third sealing element or member248 is operatively disposed between the first and second pistons to formthe substantially fluid-tight seal therebetween when second piston 234is disposed in the first position. Additionally, a fourth sealingelement or member 250 can be operatively disposed between the first andsecond pistons to form the substantially fluid-tight seal therebetweenwhen second piston 234 is disposed in the second position. It will beappreciated, however, that any other suitable arrangement couldalternately be used. Additionally, it will be understood that first,second, third and/or fourth (if provided) sealing elements, which arerespectively identified by item numbers 222, 224, 248 and 250, can beretained on or along the first or second piston in any suitable manner,such as through the use of grooves 252 that extend into first piston 204and at least partially receive a sealing element. Grooves 252 can takeany suitable shape, form and/or configuration, such as has beendescribed above with regard to groove 142, for example.

As discussed above, one or more of the sealing members (e.g., one ormore of first-fourth sealing elements 222, 224, 226 and/or 228) arecapable of actuation from a first or moveable condition to a second orcompressed condition and such actuation can be achieved in any suitablemanner. As was previously described, one or more fluid passages can beprovided that extend through the moveable wall to permit fluidcommunication between one or more of the sealing elements and thepressurized fluid contained in the storage chamber of the storagestructure. It will be appreciated that the one or more fluid passages,together with the corresponding openings or open ends thereof, can be ofany suitable size, shape, configuration and/or arrangement, and that anynumber of one or more occurrences of one or more of the fluid passagescan be used.

In the exemplary arrangement shown in FIGS. 4-6, two groups that eachinclude several fluid passages or fluid passage portions are provided inapproximately diametrically opposed sections of first piston 204. Withsecond piston 234 in the first position, as shown in FIG. 4, the fluidpassages extending through first piston 204 are substantiallyfluidically-isolated from storage chamber 210. As second piston 234 isdisplaced toward the second position, which is shown in FIG. 5, a firstpassage or passage portion 254 is disposed in fluid communication withstorage chamber 210. As such, pressurized fluid from the storage chamberis communicated to first passage portion 254. Second and third passagesor passage portions 256 and 258 are in fluid communication between firstpassage portion and the corresponding grooves of first and secondsealing elements 222 and 224, respectively. As described above, theincreased pressure from the pressurized fluid contained in storagechamber 210 acts to urge or otherwise bias the first and second sealingelements into abutting engagement with side wall 208 of the storagestructure to thereby generate a sealed condition. An optional fourthpassage or passage portion 260 is shown extending between first passageportion 254 and the groove associated with optional fourth sealingelement 250. Using the same principles of operation described above, animproved seal could be achieved between the first and second pistonswhile the second piston is in the second position shown in FIG. 5.

As an alternative to providing fourth sealing element 250 and fourthpassage portion 260, a conventional seal (not shown) could be providedon or along actuator passage 244 between first piston rod 220 and secondpiston rod 246. As another alternative, which is also not shown in thedrawings, second piston 234 could be entirely enclosed within the firstpiston, so that there is no opening to an external pressure area (i.e.,a lower pressure atmosphere ATM). A suitable electromagnetic or otheractuator could be used to displace second piston 234 between the firstand second positions, for example.

In an arrangement in which fourth sealing element 250 and fourth passageportion 260 are provided, as described above, first piston 204 canoptionally include a fifth passage or passage portion 262 that can beselectively placed in fluid communication with an external pressurearea, such as a lower pressure atmosphere ATM, for example, to at leastbriefly decrease the pressure level within fourth passage portion 260and thereby permit second piston 234 to be more easily displaced fromthe second position, which is shown in FIG. 5, to the first position,which is shown in FIG. 4. Additionally, such an arrangement and methodof operation may assist in decreasing wear on or along fourth sealingelement 250 and/or second outer peripheral wall 240 of second piston234. It will be appreciated that such selective communication alongfifth passage portion 262 can be achieved in any suitable manner, suchas by communicating an actuation signal 264 to a suitable fluid controldevice, such as a valve assembly 266, for example.

As discussed above, another feature of a moveable wall and sealingarrangement in accordance with the subject matter of the presentdisclosure involves the use of an optional migration-reducing substanceto minimize or at least reduce the migration of the pressurized fluidstored within the storage chamber beyond the sealing arrangement. Itwill be appreciated that such a substance can be provided in anysuitable manner. For example, a quantity of migration-reducing substance268 can be contained within a suitable dispensing device 270, as isillustrated in FIG. 4. It will be appreciated that such a dispensingdevice can be of any suitable type, kind, configuration and/orconstruction and, in the exemplary embodiment shown, is supported onside wall 208 of storage structure 202. Additionally, it will berecognized that first piston 204 is positioned along side wall 208 suchthat a dispensing nozzle (not numbered) of dispensing device 270 is influid communication with intermediate chamber 226. Upon achieving asubstantially fluid-tight seal, such as is illustrated in FIG. 5, forexample, a dispensing signal 272 (FIG. 4) can be communicated todispensing device 270 such that migration-reducing substance 268 istransferred into intermediate chamber 226, as is shown in greater detailin FIG. 6.

It will be appreciated that any suitable substance or combination ofsubstances can be used to form a quantity of migration-reducingsubstance, such as substance 268, for example. Additionally, it will beappreciated that the quantity of migration-reducing substance can takeany suitable form, such as a gas, a liquid, a solid or any combinationthereof. Furthermore, it will be appreciated that the quantity ofmigration-reducing substance can act to minimize or at least reduce themigration of pressurized fluid stored within the storage chamber throughor otherwise outwardly beyond the sealing arrangement, such as sealingarrangement 206, for example, in any suitable manner or combination ofmanners.

As one example, the migration-reducing substance could act alter theportion of the pressurized fluid that is captured within intermediatechamber, such as by modifying the chemical structure of the pressurizedfluid in a manner that would minimize penetration or tunneling throughone or more of the sealing elements (e.g., sealing elements 222 and224), for example. More specifically, a migration-reducing substance,such as unsaturated vegetable oil, for example, could be used toincrease the atomic or molecular size of a gas, such as hydrogen, forexample, that is contained in the storage chamber. As another example,other migration-reducing substances could be used, such as tosubstantially thicken or even solidify a pressurized fluid, for example.

As another example, the migration-reducing substance could act todecrease the magnitude of movement (i.e., Brownian motion) within thepressurized fluid contained within the intermediate chamber to therebyreduce the movement or energy of the atoms or molecules of thepressurized fluid acting on the sealing elements and thereby decreasemigration, penetration and/or tunneling of the atoms or moleculesthrough the sealing elements. As one example, intermediate chamber 226could be substantially filled with a quantity of mercury. It is expectedthat such a quantity of mercury would significantly retard the migrationof a pressurized gas, such as natural gas, for example, through thesealing elements.

A further example of a pressurized fluid storage system 300 is shown inFIGS. 7-10 that includes an alternate embodiment of a moveable wall andan interactive sealing arrangement in accordance with the subject matterof the present disclosure. It will be appreciated that storage system300 is substantially similar to pressurized fluid storage system 200shown and described hereinbefore with respect to FIGS. 4-6. Pressurizedfluid storage system 300 is shown as including a storage structure 302,such as has been described above with regard to storage structure 202,for example. Pressurized fluid storage system 300 is shown as includinga moveable wall, such as a first piston 304, for example, which is shownas being substantially similar to first piston 204. Additionally,pressurized fluid storage system 300 is shown as including aninteractive sealing arrangement 306, such as has been described abovewith regard to sealing arrangement 206, for example.

Pressurized fluid storage system 300 differs from storage system 200 inthat first piston 304 is adapted to dispense a migration-reducingsubstance, rather than utilizing a dispensing device provided on thestorage structure, such as has been described above with regard todispensing device 270 and side wall 208, for example. In view of themany similarities between storage structure 202 and 302, first pistons204 and 304, and sealing arrangements 206 and 306, the structural andoperational differences of storage system 300 will now be described withcontrasting reference to storage system 200, where applicable.

First piston 304 includes a second piston 308 that is substantiallysimilar to second piston 234. As was described above with regard tosecond piston 234, second piston 308 is selectively displaceable betweena first position, which is shown in FIG. 7, and a second position, whichis shown in FIG. 8. First piston 304 differs from first piston 204,however, in that second piston 308 is capable of displacement into athird position, which is shown in FIG. 9. As was described above, in thefirst position with regard to the displacement of second piston 234,second piston 308 substantially fluidically-isolates each group of fluidpassages 310 of first piston 304 from a storage chamber 312 of storagestructure 302, such as through the use of a sealing element or member314, for example. In the second position, second piston 308 permits eachgroup of fluid passages 310 to fluidically communicate with storagechamber 312 and thereby actuate or otherwise bias sealing elements316-320, such as has been previously described.

It will be recognized, however, that sealing arrangement 306 includes anadditional (i.e., a fifth) sealing element or member 322, in contrast tosealing arrangement 206, that sealingly engages second piston 308 in thesecond position. As mentioned above, fluid passages 310 are in fluidcommunication with the storage chamber when the second piston is in thesecond position. However, the inclusion of this additional sealingelement substantially fluidically-isolates one or more dispensingpassages 324 that extend through first piston 304. The one or moredispensing passages extend in fluid communication between an actuationcavity 326 of first piston 304 and an intermediate chamber 328 that isat least partially defined between sealing elements 316 and 318. Aquantity of a suitable migration-reducing substance (not shown), such ashas been previously discussed, for example, can be contained within theone or more dispensing passages. Additionally, an optionalsubstance-storage chamber 330 could be provided to increase the quantityof the migration-reducing substance that is available to be dispensed.

Upon movement of second piston 308 from the second position toward thethird position, which is shown in FIG. 9, a first open end 332 ofdispensing passages 324 is exposed or otherwise placed into fluidcommunication with the pressurized fluid contained in storage chamber312, such as by way of a gap or opening 334 (FIG. 9) formed betweensecond piston 308 and sealing element 322, for example. Exposure of thedispensing passages to the elevated pressure level of the fluid withinthe storage chamber can act to urge or otherwise dispense at least aportion of the migration-reducing substance from the dispensing passagesand/or the substance-storage chamber, if provided. Optionally, a gate336 or other suitable component could be disposed along second open end338 of dispensing passages 324, as is shown in FIG. 10. Gate 336, ifprovided, can be secured on or along first piston 304 in any suitablemanner. For example, the gate could be pivotally attached to the firstpiston and open in a radially-outward direction, such as if operatinglike a trap door, for example. As another example, gate 336 could extendcircumferentially about first piston 304 and could be displaced in anaxial direction to expose second open end 338, as is shown in FIG. 10,for example.

Still a further example of a pressurized fluid storage system 400 isshown in FIG. 11 that includes an alternate embodiment of a moveablewall and an interactive sealing arrangement in accordance with thesubject matter of the present disclosure. Pressurized fluid storagesystem 400 includes a storage structure 402, such as has been describedabove with regard to storage structures 102, 202 and 302, for example.Pressurized fluid storage system 400 is shown as including a moveablewall, such as a first piston 404, for example, which is shown as beingsomewhat similar to first pistons 204 and 304, for example.Additionally, pressurized fluid storage system 400 is shown as includingan interactive sealing arrangement 406, such as has been generallydescribed above with regard to sealing arrangements 206 and 306, forexample.

Storage structure 402 is shown as including a first or side wall 408that at least partially defines a longitudinally-extending storagechamber 410 having a longitudinal axis AX. It will be appreciated thatside wall 408 and storage chamber 410 can be of any suitable type, kind,construction and/or configuration, such as has been described above indetail with regard to storage structures 102, 202 and 302, for example.As such, a further description of storage structure 402 is not providedhere.

First piston 404 is received within storage structure 402 and includes asecond piston 412 that is telescopically received within first piston404, such as has been previously described. Second piston 412 is adaptedfor reciprocal displacement between a first position, which is shown inFIG. 11, and a second position, which is represented by dashed line 414in FIG. 11. First piston 404 also includes at least one fluid passage416 that extends in fluid communication between an actuation cavity 418and at least a portion of an outer peripheral wall 420 of first piston404, such as a bottom wall (not numbered) of a groove 422, which can beoptionally provided, that extends circumferentially about the firstpiston, for example.

Sealing arrangement 406 can include any number of one or more sealingelements, such as has been discussed above with regard to sealingarrangements 106, 206 and 306, for example. In the exemplary embodimentshown in FIG. 11, sealing arrangement 406 includes a first sealingelement or member 424 that is disposed along outer peripheral wall 420of first piston 404, such as by being at least partially received withingroove 422, for example. Sealing arrangement 406 also includes secondand third sealing elements or members 426 and 428 that are disposedalong an inner side wall (not numbered) that at least partially definesactuation cavity 418, such as, for example, within grooves 430 that canbe optionally provided and can extend circumferentially about actuationcavity 418.

Second and third sealing elements 426 and 428 are disposed in spacedrelation to one another and fluid passage 416 is in fluid communicationwith actuation cavity at a location between the second and third sealingelements. As such, in the first position, second piston 412substantially fluidically-isolates fluid passage 416 from thepressurized fluid contained in storage chamber 410 due to thesubstantially fluid-tight seal formed by second sealing element 426between the first and second pistons. As the second piston istransferred to the second position, fluid passage 416 is placed in fluidcommunication with the pressurized fluid contained in storage chamber410, which pressurized fluid acts to bias or otherwise urge firstsealing element 424 in a radially-outward direction to at leastpartially form a substantially fluid-tight seal between first piston 404and side wall 408 of the storage structure, such as has been describedin detail hereinbefore. Third sealing element 428 can sealingly engagesecond piston 412 in the second position to form a substantiallyfluid-tight seal between the first and second pistons and therebyprevent or at least minimize the transfer pressurized fluid from thestorage chamber to an external pressure area, such as a lower pressureatmosphere ATM, for example, when the first piston is in a sealedcondition.

Sealing arrangement 406 also includes fourth and fifth sealing elementsor members 432 and 434 that are disposed in axially-spaced relation toone another along outer peripheral wall 420 of first piston 404. Fourthand fifth sealing elements 432 and 434 are shown as being received incircumferentially-extending grooves, which can be optionally providedalong first piston 404. As shown in FIG. 11, fourth sealing element 432is disposed in axially-spaced relation to first sealing element 424 suchthat a first intermediate chamber 436 is at least partially definedtherebetween. Fifth sealing element 434 is positioned opposite the firstsealing arrangement such that a second intermediate chamber 438 is atleast partially defined between the fourth and fifth sealing elements.The first and second intermediate chambers are also at least partiallydefined by outer peripheral wall 420 of the first piston and side wall408 of the storage structure.

First piston 404 and sealing arrangement 406 differ from previouslydescribed piston and sealing arrangements in that an additional portionof sealing element 432 (e.g., a portion disposed toward the bottom wallof the groove in which the sealing element is received) is exposed tothe pressurized fluid contained in first intermediate chamber 436,rather than being directly exposed to the pressurized fluid containedwithin the storage chamber. This additional portion includes a sectionor surface area in addition to the portion of sealing element 432 thatat least partially defines intermediate chamber 436. Similarly, anadditional portion of sealing element 434 (e.g., a portion disposedtoward the bottom wall of the groove in which the sealing element isreceived) is exposed to the pressurized fluid contained in secondintermediate chamber 438. In this manner, the differential pressure fromstorage chamber 410 to lower pressure atmosphere ATM could bestepped-down at intermediate pressure levels in each of the intermediatechambers. Accordingly, it is expected that the differential pressureacting on any one sealing element could be reduced through the use ofone or more intermediate or step-down sealing arrangements in which aportion of a sealing element is fluidically interconnected with acorresponding intermediate chamber. Additionally, it will be appreciatedthat any suitable number of such one or more intermediate or step-downsealing arrangements can be used (e.g., from 1 to 20 intermediatearrangements spaced apart from one another).

It will be appreciated that such a step-down pressure differential canbe achieved in any suitable manner using any suitable structuralelements and/or features. In the exemplary embodiment shown in FIG. 11,for example, first piston 404 includes a first intermediate passage 440that extends in fluid communication between first intermediate chamber436 and fourth sealing element 432. Additionally, first piston 404includes a second intermediate passage 442 that extends in fluidcommunication between second intermediate chamber 438 and fifth sealingelement 434.

It will be recognized, however, that the step-down sealing arrangementdescribed above will operate in a natural and largely uncontrolledmanner. That is, as pressurized fluid from storage chamber 410 passesinto first intermediate chamber 436 and the pressure level increases,fourth sealing element 432 will be increasingly urged into sealingengagement with side wall 408. Similarly, as pressurized fluid fromfirst intermediate chamber 436 passes into second intermediate chamber438, the pressure level within the second intermediate chamber would beexpected to increase and thereby increasingly urge fifth sealing element434 into greater sealing engagement with the side wall. Additionally, orin the alternative, localized deflection of a sealing element intoand/or otherwise along a gap or clearance 444 (e.g., gap or clearance138 and/or 218) between the moveable wall and the side wall of thestorage structure may also contribute to any increased in pressurewithin the first and/or second intermediate chambers.

In some cases, the natural and largely uncontrolled operation of theabove-described step-down sealing arrangement may be beneficial, such asdue to the simplicity of operation and lack of use of additionalcomponents, for example. However, in other cases, it may be desirable toprovide some level of control over the flow of pressurized fluid throughone or more of the intermediate passages, such as, for example, toensure that one or more of the sealing elements are actuated in apredetermined sequence and/or at predetermined pressure levels.

As such, first piston 404 and/or sealing arrangement 406 can optionallyinclude any suitable number of one or more fluid control devices thatoperate to permit and prohibit fluid flow along a corresponding one ormore of the intermediate passages. For example, first piston 404 isshown in FIG. 11 as including first fluid control devices, which areschematically represented by boxes 446, that are disposed in fluidcommunication along first intermediate passages 440. Additionally, or inthe alternative, second fluid control devices can, optionally, beprovided in fluid communication along second intermediate passage 442.The second fluid control devices are schematically represented in FIG.11 by boxes 448.

As indicated above, it will be appreciated that first and second fluidcontrol devices 446 and 448 can be of any suitable type, kind,configuration and/or construction and that the same can be actuated orotherwise operated in any suitable manner and/or in connection with anyadditional devices, components and/or systems that may be suitable foruse in connection with the operation thereof. As one example, the firstand second fluid control devices could be valves that are selectivelyoperable through the use of electrical solenoids (not shown) orpneumatic actuators (not shown). And, selective operation of the fluidcontrol devices could be initiated or otherwise handled by a controller(not shown) in response to inputs, such as, for example, a time periodfrom a counter or timer, a pressure level from a pressure transducer orpressure sensor, a temperature level from a thermocouple or temperatureprobe, and/or a position or orientation identified by a proximity sensoror encoder.

As another example, first and second fluid control devices 446 and 448could include pressure actuated valves, such as one-way spring-biasedcheck valves, for example, that are respectively disposed in fluidcommunication along first and second intermediate passages 440 and 442.In one case, the first and second fluid control devices could besubstantially identical to one another, such that the valves open andclose at approximately the same pressure level. In a preferredarrangement, however, first fluid control devices 446 are actuated at apressure level that is substantially greater than the pressure level atwhich second fluid control devices 448 are actuated. It will beappreciated, however, that other arrangements could alternately be used.

With more specific reference to the foregoing example, a pressurizedfluid storage system in accordance with the subject matter of thepresent concept is anticipated to be capable of containing fluids atpressures well in excess of 5,000 psi, such as pressure levels within arange of from 10,000 to 50,000 psi (or greater), for example. It isassumed for explanatory purposes that a quantity of fluid is beingstored within storage chamber 410 at a pressure of approximately 30,000psi. In such case and further to this example, the valves of first fluidcontrol devices 446 could be configured in a normally-closed conditionand configured to change to an open condition at a fluid pressure levelof approximately 20,000 psi. With still further reference to thisexample, the valves of second fluid control devices 448 could beconfigured in a normally-closed condition and configured to change to anopen condition at a fluid pressure level of approximately 10,000 psi. Insuch case, it will be recognized that first intermediate chamber 436would be expected to equalize at a pressure level of approximately20,000 psi and that second intermediate chamber 438 would be expected toequalize at a pressure level of approximately 10,000 psi. In such case,a step-down pressure differential of approximately 10,000 psi will begenerated across each of sealing elements 424, 432 and 434.

Generally, it is expected that, during use, a first reduced pressurelevel (P₁) will be achieved in first intermediate chamber 436 and thatthe first reduced pressure level will be less than the pressure level(P_(S)) of the pressurized fluid contained in storage chamber 410, suchas, for example, once the interactive seal formed by first sealingelement 424 has been achieved. The pressurized gas in the firstintermediate chamber will, by way of first intermediate passage 440,urge fourth sealing element 432 into sealing engagement between thefirst piston and the side wall of the storage structure. In turn, it isexpected that a second reduced pressure level (P₂) will be reached insecond intermediate chamber 438 and that the second reduced pressurelevel will be less than the first reduced pressure level in the firstintermediate chamber, such as, for example, once the interactive sealformed by fourth sealing element 432 has been achieved. As a result, thedifferential pressure between the second reduced pressure level andlower pressure atmosphere ATM is expected to be significantly less thanthe differential pressure between the pressure level of the storagechamber and the lower pressure atmosphere. This is expected to result ina more robust and/or increasingly effective sealing arrangement.

As discussed above, a sealing arrangement in accordance with the subjectmatter of the present disclosure can included one or more sealingelements or members of any suitable size, shape, configuration,construction and/or arrangement. For example, the one or more sealingmembers or elements could have a circular, oval, rectangular or othercross-sectional shape (e.g., quad-ring). Additionally, the one or moresealing members or elements can be formed from any suitable material orcombination of materials. It will be recognized that the sealingelements shown in FIGS. 1-11 have an oval or otherwise somewhat circularcross-sectional shape, such as may be found in a conventional O-ring,for example.

Another embodiment of a sealing element or member 500 is shown in FIG.12 that could alternately be used as one or more of the sealing elementsin a sealing arrangement in accordance with the subject matter of thepresent disclosure, such as has been described with regard to sealingarrangements 106, 206, 306 and 406, for example. Sealing element 500 isshown in FIG. 12 as being operatively disposed between piston 104 andside wall 108 of storage structure 102, as are shown in Detail 12 inFIG. 2. Additionally, sealing element 500 is shown in an actuated orradially-outwardly biased condition suitable for forming a substantiallyfluid-tight seal between the piston and the side wall of the storagestructure. A dashed box 500′ having a substantially rectangular shaperepresents the sealing element in a condition suitable for movement ofpiston 104.

As the pressure of the fluid (e.g., liquid and/or gas) within storagechamber 110 increases, the pressure within passage 148 will alsoincrease. This increased pressure will act on one portion of sealingelement 500 (e.g., inner surface 502 thereof), as shown by arrows AR2,which thereby forces another portion of sealing element 500 (e.g., outersurface 504) outwardly and into abutting engagement with first wall 108of container 102 such that a substantially fluid-tight seal can beformed therewith. In a preferred arrangement, membrane 120 will becooperative with one or more of the features (e.g., bottom wall 144and/or side walls 146) of groove 142 such that a substantiallyfluid-tight seal is similarly provided or maintained between the sealingelement and the piston.

A further embodiment of a sealing element or member 600 is shown in FIG.13 that could alternately be used as one or more of the sealing elementsin a sealing arrangement in accordance with the subject matter of thepresent disclosure, such as has been described with regard to sealingarrangements 106, 206, 306 and 406, for example. Sealing element 600 isshown in FIG. 13 as being operatively disposed between piston 104 andside wall 108 of storage structure 102, as are shown in Detail 12 inFIG. 2. Additionally, sealing element 600 is shown in an actuated orradially-outwardly biased condition suitable for forming a substantiallyfluid-tight seal between the piston and the side wall of the storagestructure. An unbiased condition of the sealing element that would besuitable form movement of piston 104 is not shown.

Sealing element 600 is similar to sealing element 500 in overall shape.Sealing element 600 differs from sealing element 500, however, in thatsealing element 600 includes an outer body 602 that is at leastpartially filled with a liquid 604. It is believed that localizeddeflection along an inner surface 606 in the area of openings 152 wouldgenerate displacement of liquid 604, which, in turn, would assist inforcing an outer surface 608 against first wall 108, as described above.Additionally, or in the alternative, a coating, layer or other surfacetreatment can optionally be applied along any one or more portions ofthe sealing member, such as to provide abrasion resistance, improvedsealing, adhesion and/or strength/stiffness. For example, an optionalcoating 610 is shown as being disposed along inner surface 606.

Still another example of a sealing element of member 700 is shown inFIGS. 14-16 that could alternately be used as one or more of the sealingelements in a sealing arrangement in accordance with the subject matterof the present disclosure, such as has been described with regard tosealing arrangements 106, 206, 306 and 406, for example. Sealing element700 is shown in FIGS. 14-16 as being operatively disposed between piston104 and side wall 108 of storage structure 102, as are shown in Detail12 in FIG. 2. Additionally, sealing element 700 is shown in an actuatedor radially-outwardly biased condition suitable for forming asubstantially fluid-tight seal between the piston and the side wall ofthe storage structure. An unbiased condition of the sealing element thatwould be suitable form movement of piston 104 is not shown.

Sealing element 700 is shown in FIGS. 14-16 as taking the form of athin-walled membrane. It will be appreciated that such a thin-walledmembrane can take any suitable shape or configuration. In the exemplaryarrangement shown in FIGS. 14-16, sealing element 700 has a U-shapedcross section that includes an outside surface 702 and an inside surface704 that at least partially defines a seal chamber 706. The U-shapedcross section of sealing element 700 also includes a firstradially-extending side portion 708, a second radially-extending sideportion 710 that is disposed in spaced relation to the first sideportion, and an end portion 712 that extends in an approximatelylongitudinal direction therebetween.

Sealing element 700 is disposed along an outer peripheral wall (notnumbered) of piston 104. In a preferred embodiment, as is shown in FIGS.14 and 16, sealing element 700 is cooperatively received in groove 142such that first side portion 708 is disposed adjacent one of the sidewalls (e.g., side walls 146) of groove 142 and second side portion 710is disposed adjacent the other side wall of groove 142.

As the pressure of the fluid (e.g., liquid and/or gas) within storagechamber 110 increases, the pressure within passage 148 will alsoincrease. This increased pressure will act on one portion of sealingelement 700 (e.g., inside surface 704), as shown by arrows AR2, whichthereby forces end portion 712 outwardly and into abutting engagementwith first wall 108 of storage structure 102 such that a substantiallyfluid-tight seal can be formed therewith, as has been described above indetail.

In a preferred arrangement, at least a portion of sealing element 700can be secured on or along piston 104 in any suitable manner such that asubstantially fluid-tight seal is formed between the sealing element andthe piston. In the exemplary arrangement shown in FIGS. 14 and 16, firstradially-extending side portion 708 is secured on or along side wall 146of groove 142, such as through the use of a suitable adhesive or sealant714, for example. Optionally, second radially-extending side portion 710can be secured on or along side wall 146 of groove 142, such as throughthe use of a suitable adhesive or sealant 716. It will be appreciatedthat the suitability of a particular adhesive or sealant will vary fromapplication-to-application depending upon factors such as chemicalcompatibility and the magnitude of forces involved.

Optionally, first radially-extending side portion 708 and/or secondradially-extending side portion 710 can include one or more featuressuitable for operatively interengaging a corresponding one of the sidewalls (e.g., side walls 146) of groove 142. As one example, a pluralityof annular projections 718 are shown in FIGS. 14 and 16 as projectingoutwardly from first side portion 708 toward the corresponding side wallof groove 142. Additionally, the side wall of the groove, such as sidewall 146, for example, can optionally include one or more features forreceiving the projections, such as annular recesses 720 in FIGS. 14 and16, for example. It will be appreciated, however, that any othersuitable features or combination of features in any suitable arrangementand/or configuration could alternately be used.

Optionally, a sealing arrangement in accordance with the subject matterof the present disclosure, such as arrangements 106, 206, 306 and 406,for example, could include a suitable liquid disposed within one or moreof the fluid passages thereof. Additionally, it will be appreciated thatany suitable sealing element or members can be used in connection withsuch a sealing arrangement, such as sealing elements 140, 500, 600and/or 700, for example. In such an arrangement, the liquid could beused where the transfer of pressure is desired to be achieved with aminimum displacement. Any suitable type of membrane or sealingarrangement could be used to retain the liquid within the one or morefluid passages.

In the exemplary configuration shown in FIG. 16, a second sealingelement 722 is disposed along fluid passage 148. Second sealing element722 acts to retain a quantity of liquid 724 in seal chamber 706 and theportion of fluid passage 148 that is in fluid communication with sealchamber 706. It will be appreciated that any suitable liquid, such asmigration-reducing substance 268, for example, can be used.

As mentioned above, the thin-walled membrane that at least partiallyforms sealing element 700 can be formed in any suitable manner and fromany suitable material or combination of materials. For example, anenlarged portion of sealing element 700 is shown in cross-section inFIG. 15 that includes a first or structural portion 726 and a second orfiller portion 728. Additionally, an optional third or inside coatingportion 730 and/or an optional fourth or outside coating portion 732could be provided on or along the sealing element. Again, it will beappreciated that the suitability of particular materials and/or wallthicknesses will vary from application-to-application depending uponfactors such as chemical compatibility and the magnitude of forcesinvolved.

As one example, structural portion 726 of the thin-walled membrane couldfor formed from a suitable filament or wire-like material, such as anatural fiber cloth, a polymeric screen or cloth, a metal (e.g., steelor copper) screen or mesh or any combination thereof, for example, toprovide strength to the thin-walled membrane while maintainingsufficient flexibility to form a substantially fluid-tight seal, as hasbe previously described. Filler portion 728 can act to fill or cover anyopenings or gaps formed in the structural portion, such as the openingsformed by a mesh or screen material, for example. As shown in FIG. 15,filler or barrier material 728 substantially fully encapsulatesstructural portion 726. Additionally, the filler or barrier material ispreferably selected to be sufficiently flexible to form thesubstantially fluid-tight seal, as has been previously described, whileat least partially providing a barrier to migration of the pressurizedfluid contained in the storage structure. The optional third and/orfourth portions (e.g., portions 730 and/or 732) can be formed from anymaterial or combination of materials, such as, for example, may besuitable for further reducing migration of the pressurized fluid orforming a beneficial interrelationship with a liquid ormigration-reducing substance, such as liquid 724 and/or migrationreducing substance 268, for example.

Examples of materials that may be suitable for use as a barrier materialand/or a coating material are metals, such as gold, lead and/or tin, forexample, as well as polymeric materials, such as PTFE, for example. Oneadvantage of the use of metallic materials over polymeric materials isthat many gases, such as could be stored using a pressurized fluidstorage system utilizing sealing arrangement in accordance with thesubject matter of the present disclosure, may penetrate and/or degradepolymeric materials more quickly than may occur with metallic materials.Another advantage of using a metal as a barrier and/or coating materialis that metals, such as gold, lead and tin, for example, are capable ofproviding other physical characteristics and/or properties that may bedesired, such as increased flexibility, for example. A further advantagethat may be associated with the use of such metal materials is that thesame can be made to or will otherwise readily adhere to one anotherwithout the use of adhesives, such as by forming an amalgam, forexample. One benefit of adhering materials together in this manner isthat the use of a separate adhesive can be avoided. And, it will beappreciated that such adhesives are often polymer-based and, thus, maybe undesirably affected by exposure to certain atoms, molecules and/orsubstances that might be contained within a pressurized fluid storagesystem in accordance with the subject matter of the present disclosure.Additionally, it will be appreciated that one or more layers of first,second, third and/or fourth portions 726-732 could optionally be used.That is, a multi-layered construction that includes one or more firstportions, one or more second portions, one or more third portions and/orone or more fourth portions, in any order, arrangement and/orconfiguration, could be used.

It will be recognized that numerous different features and/or componentsare presented in the embodiments shown and described herein, and that noone embodiment is specifically shown and described as including all suchfeatures and components. However, it is to be understood that thesubject matter of the present disclosure is intended to encompass anyand all combinations of the different features and components that areshown and described herein, and, without limitation, that any suitablearrangement of features and components, in any combination, can be used.Thus it is to be distinctly understood claims directed to any suchcombination of features and/or components, whether or not specificallyembodied herein, are intended to find support in the present disclosure.

Thus, while the subject matter of the present disclosure has beendescribed with reference to the foregoing embodiments and considerableemphasis has been placed herein on the structures and structuralinterrelationships between the component parts of the embodimentsdisclosed, it will be appreciated that other embodiments can be made andthat many changes can be made in the embodiments illustrated anddescribed without departing from the principles hereof. Obviously,modifications and alterations will occur to others upon reading andunderstanding the preceding detailed description. Accordingly, it is tobe distinctly understood that the foregoing descriptive matter is to beinterpreted merely as illustrative of the subject matter of the presentdisclosure and not as a limitation. As such, it is intended that thesubject matter of the present disclosure be construed as including allsuch modifications and alterations insofar as they come within the scopeof the appended claims and any equivalents thereof.

1. A pressurized fluid storage system for containing a quantity of anassociated fluid at an elevated pressure level, said system comprising:a pressure vessel including a vessel wall that at least partiallydefines a storage chamber for storing a quantity of the associatedfluid, said vessel wall including an opening providing access to saidstorage chamber; a moveable wall structure displaceably supported withinsaid pressure vessel and extending across said opening to at leastpartially retain a quantity of the associated fluid in said storagechamber, said moveable wall structure including: an outer peripheralwall disposed adjacent said vessel wall such that a gap is formedbetween said outer peripheral wall and said vessel wall; an end walldisposed toward said storage chamber; a groove extending into saidmoveable wall structure from along said outer peripheral wall such thatsaid groove is in fluid communication with said storage chamber throughsaid gap; and, at least one passage extending through at least a portionof said moveable wall structure and in fluid communication between saidgroove and said storage chamber; and, an interactive sealing arrangementoperatively disposed between said pressure vessel and said moveable wallstructure and capable of forming a substantially fluid-tight sealtherebetween, said interactive sealing arrangement including: a firstsealing member positioned between said moveable wall structure and saidvessel wall and disposed at least partially within said groove of saidmoveable wall structure, said first sealing member including a firstperipheral portion disposed toward said vessel wall and a secondperipheral portion disposed along said groove in fluid communicationwith said at least one passage such that a portion of the associatedfluid at an elevated pressure within said storage chamber can interactwith said second peripheral portion of said first sealing member andthereby urge said first peripheral portion of said first sealing memberinto abutting engagement with said vessel wall of said pressure vessel.2. A system according to claim 1, wherein said at least one passageincludes a first passage having a first end in fluid communication withsaid groove and an opposing second end in fluid communication with saidstorage chamber.
 3. A system according to claim 2, wherein said sealingarrangement includes a piston supported on said moveable wall structurethat is displaceable between a first position on said moveable wallstructure in which said second end of said passage is substantiallyfluidically-isolated from said storage chamber and a second position onsaid moveable wall structure in which said second end of said passage isin fluid communication with said storage chamber.
 4. A system accordingto claim 3, wherein said sealing arrangement includes a second sealingmember supported on one of said moveable wall structure and said pistonand operative to form a substantially fluid-tight seal between saidmoveable wall structure and said piston in at least said first positionof said piston.
 5. A system according to claim 4, wherein said secondsealing member is supported on said moveable wall structure and saidsealing arrangement includes a third sealing member supported on saidmoveable wall structure in spaced relation to said second sealing membersuch that said third sealing member forms a substantially fluid-tightseal between said moveable wall structure and said piston said secondposition of said piston.
 6. A system according to claim 5, wherein saidgroove extending into said moveable wall structure is a first groove andsaid moveable wall structure includes a second groove extendingthereinto adjacent said piston, said third sealing member includes afirst peripheral portion disposed toward said piston and a secondperipheral portion disposed along said second groove, said at least onepassage is disposed in fluid communication between said first groove,said second groove and said storage chamber in said second position ofsaid piston such that a portion of the associated fluid at an elevatedpressure within said storage chamber can interact with said secondperipheral portion of said first and third sealing members and therebyurge said first peripheral portion of said first sealing member intoabutting engagement with said vessel wall of said pressure vessel andsaid first peripheral portion of said third sealing member into abuttingengagement with said piston.
 7. A system according to claim 6, whereinsaid at least one passage includes a first passage having a firstportion with a first end in fluid communication with said first groove,a second portion with a second end in fluid communication with saidsecond groove and a third portion with a third end in fluidcommunication with said storage chamber.
 8. A system according to claim7, wherein said first passage is one of a plurality of first passagesdisposed in circumferentially-spaced relation to one another about saidmoveable wall structure.
 9. A system according to claim 7, wherein saidthird end of said third portion of said first passage is fluidicallyisolated from said storage chamber in said first position of saidpiston.
 10. A system according to claim 6, wherein said moveable wallstructure includes a third groove extending thereinto from along saidouter peripheral wall and in spaced relation along said outer peripheralwall from said first groove, and said interactive sealing arrangementincludes a fourth sealing member at least partially disposed within saidthird groove of said moveable wall structure such that a portion of saidgap disposed between said first and fourth sealing members at leastpartially defines an intermediate chamber.
 11. A system according toclaim 10, wherein said at least one passage includes a first passagehaving a first portion with a first end in fluid communication with saidfirst groove, a second portion with a second end in fluid communicationwith said second groove, a third portion with a third end in fluidcommunication with said storage chamber, and a fourth portion with afourth end in fluid communication with said third groove.
 12. A systemaccording to claim 6, wherein said at least one passage includes a firstpassage having a first portion with a first end in fluid communicationwith said first groove, a second portion with a second end in fluidcommunication with said second groove and a third portion with a thirdend in fluid communication with said storage chamber, and said moveablewall structure includes an exhaust passage in fluid communicationbetween said first passage and an associated external atmosphere.
 13. Asystem according to claim 12, wherein said interactive sealingarrangement includes a valve in fluid communication across said exhaustpassage, said valve being selectively operable to permit fluid flowthrough said exhaust passage. 14.-26. (canceled)
 27. A system accordingto claim 1, wherein said at least one passage includes a first passagehaving a first portion with a first end in fluid communication with saidfirst groove and a second portion with a second end in fluidcommunication said storage chamber, and a second passage in fluidcommunication between said intermediate chamber and said second groove.28. A system according to claim 27, said first passage is one of aplurality of first passages disposed in circumferentially-spacedrelation to one another about said moveable wall structure, and saidsecond passage is one of a plurality of second passages disposed incircumferentially-spaced relation to one another about said moveablewall structure.
 29. A system according to claim 27, wherein said secondsealing member includes a first peripheral portion disposed toward saidvessel wall and a second peripheral portion disposed along said secondgroove such that at least a portion of the associated fluid at anelevated pressure within said intermediate chamber can interact withsaid second peripheral portion of said second sealing member throughsaid second passage and thereby urge said first peripheral portion ofsaid second sealing members into abutting engagement with said vesselwall of said pressure vessel.
 30. A system according to claim 27,wherein said interactive sealing arrangement includes a valve in fluidcommunication across said second passage, said valve being selectivelyoperable to permit fluid flow through said second passage.
 31. A systemaccording to claim 27, wherein said intermediate chamber is a firstintermediate chamber, said moveable wall structure includes a thirdgroove extending thereinto from along said outer peripheral wall and inspaced relation along said outer peripheral wall from said second groovein a direction generally opposite said first groove, and saidinteractive sealing arrangement includes a third sealing memberpositioned between said moveable wall structure and said vessel wall anddisposed at least partially within said third groove of said moveablewall structure such that a portion of said gap is disposed between saidsecond and third sealing members at least partially defines a secondintermediate chamber.
 32. A system according to claim 31, wherein saidat least one passage includes a third passage in fluid communicationbetween said second intermediate chamber and said third groove.
 33. Asystem according to claim 32, said third passage is one of a pluralityof third passages disposed in circumferentially-spaced relation to oneanother about said moveable wall structure.
 34. A system according toclaim 32, wherein said valve is a first valve and said interactivesealing arrangement includes a second valve in fluid communicationacross said third passage, said second valve being selectively operableto permit fluid flow through said third passage. 35.-78. (canceled)